PRESSURE CONTROL IN RESPIRATORY TREATMENT APPARATUS

A pressure-limit control device to prevent an over-pressure condition of a respiratory treatment apparatus, the device comprising a first circuit configured to detect a signal representative of a measure of pressure exceeding a first threshold, the first threshold representative of a first pressure limit, and to detect the exceeding of the first threshold by a second threshold, the second threshold representing a first time limit; and a second circuit configured to detect the signal representative of a measure of pressure exceeding a third threshold, the third threshold representative of a second pressure limit, and to detect the exceeding of the third threshold by a fourth threshold, the fourth threshold representing a second time limit; wherein the first and second pressure limits are different pressure limits and the first and second time limits are different time limits, and wherein a detection by either one of the first circuit and second circuit indicates an over-pressure condition of the respiratory treatment apparatus.